Assembly fixture for constructing superheated and/or reheater modules

ABSTRACT

A fixture for shop assembly of superheater and/or reheater modules including a structural frame having accurately machined surfaces to enable exact positioning of a segment of a superheater or reheater header in a particular orientation with respect to a lifting and shipping frame mounted on a fixed reference base. The module may then be completed by placing individual superheater or reheater tube panels in the frame and joining them to the header.

United States Patent Inventor Milton C. Everett Nassau County, N.Y.Appl. No. 742,206

Filed July 3, 1968 Patented Dec. 28, 1971 Assignee Kastar, Inc., NewYork BAND CLAMP 24 Claims, 4 Drawing Figs.

U.S. Cl 29/224, 81 /9.3

Int. Cl B23p 15 10 Field of Search 29/222,

References Cited UNITED STATES PATENTS 7/1940 Miller 29/222 6/1934 Dumke29/222X l/1950 Ray 81/93 2/1951 Hull 74/405 6/1952 Conklin 81/9.3 4/1968Kyser 29/222 Primary Examiner-Granville Y. Custer, Jr. AssistantExaminer-J. C. Peters A ttorneys Eackgnlaach and LackeggagliABSTRACTTCBITimBhW idjiiifi'e worirTdr'iQHEhd clamp provided with rapidtakeup and release particularly adapted for use as a ring compressor.

PATENTEDBECZSISR $629,924

INVENTOR- MILTON C. EVERETT ATTORNEYS BAND CLAMP This invention relatesto band clamps and, more particularly, to band clamps constructed andarranged for utilization as piston ring compressors.

Band type clamps are utilized as piston ring compressors to compresspiston rings into the grooves of a piston preparatory to assembly of thepiston with a cylinder.

Such band type clamps and ring compressors have heretofore beensuggested utilizing a shaft supported in a bearing assembly and one ormore straps connected with the bearing assembly and the shaft so thatupon rotation of the shaft the strap or straps will be wound thereuponto effect a change in circumference with releaseable ratchet one-wayclutch means being provided between the bearing assembly and the shaftto maintain strap tension after tightening.

Such band-type clamps or ring compressors as described above, and otherring compressors such as are known in the prior art have not, however,been entirely satisfactory since they were not generally capable ofcontinuous adjustments, capable of being rapidly adjusted for use uponpistons of widely diverse sizes, did not provide sufficient mechanicaladvantage to enable firm tightening to be accomplished easily and/orrequired complex or time consuming re-setting after removal from onepiston and before application to a subsequent piston.

Having in mind each and every one of the foregoing, it is a primaryobject of the present invention to provide novel and improved band-typeclamp sturctures and apparatus.

Another primary object of the present invention, in addition to theforegoing object, is the provision of such band-type clamps constructedand arranged for particular utility as piston ring compressors.

Yet another primary object of the present invention, in addition to eachof the foregoing objects, is the provision of such clamps which may berapidly and easily adjusted to widely diverse sizes.

Yet still further, it is another primary object of the presentinvention, in addition to each of the foregoing objects, to provide suchclamps which may be rapidly and easily tightened.

Another and still further prjmary biecrof the present invention, inaddition to each of the foregoing objects, is the &v@n of such clan pswhich may be rapidly and easily released or expanded.

Another and yet still further primary object of the present invention,in addition to each of the foregoing objects, is the provision of suchclamps which provide a substantial mechanical advantage to enable firmand complete constriction and tightening thereof with a minimum ofeffort.

In addition to each of the foregoing objects, it is yet another primaryobject of the present invention to provide such clamps which will notinadvertently be released.

Yet further, in addition to the foregoing objects, it is another primaryobject of the present invention to provide such clamps which may bereadily operated without requiring the utilization of special tools.

Yet still further, it is another primary object of the presentinvention, in addition to each of the foregoing objects, to provide suchclamps which are long-lasting and durable while being yet simple andeasy to manufacture.

Yet still further, it is another primary object of the presentinvention, in addition to each of the foregoing objects, to provide suchclamps which are simple and easy to use and capable of a wide range ofcontinuous adjustments.

Yet still further, in addition to each of the foregoing objects, it isyet still another primary object of the present invention to providesuch clamps with novel worm drive and ratcheting means.

The invention resides in the combination, construction, arrangement anddisposition of the various component parts and elements incorporated inimproved band-type clamps constructed in accordance with the principlesof the present invention. This invention will be better understood whenconsideration is given to the following details and description which,when taken in conjunction with the annexed drawing, describes,discloses, illustrates and shows a preferred embodiment or modificationof the present invention and what is presently considered and believedto be the best mode of practicing the principles thereof. Otherembodiments or modifications may be suggested to those having thebenefit of the teachings herein, and such other embodiments ormodifications are intended to be reserved especially as they fall withinthe scope and spirit of the subjoined claims. t 9 ra ins FIG. 1 is aside elevational view of a'ring compressor constructed in accordancewith the principles of the present invention;

FIG. 2 is a top cross-sectional partial view taken along FIG. 3 is a topcross-sectional plan, partial view taken along line 3-3 of FIG. 1; andFlGjmn elaatiorial cross-sectional view taken along li ,I@t.2.-

With reference now to the drawing, there is shown and illustrated newand improved ring compressor apparatus 'co rstructed in accordancewithlh principles of the present invention and designated generally bythe reference character 10 which comprises a band 12 adapted to bedisposed generally circumferentially about, for example, a piston 14 anda band-type clamp assembly 16 for constricting the band 12, as will bedescribed in more detail hereinafter.

The band-type clamp 16 may, in turn, comprise a bearing assembly orbracket 18, a worm gear assembly 20 rotationally carried thereby, apivot bracket 22 structurally associated with the bearing assembly ormain bracket 18, a worm screw bracket 24 pivotally associated with thepivot bracket 22, and one or more elongated straps 26 structurallyassociated with the bearing assembly or main bracket 18 and worm gearassembly 20 as hereinafter more fully described. N

One end portion of the strap 26 may be secured with the bearing assemblyor main bracket 18, as by means of rivets '28 extending through holes 30provided adjacent one end portion thereof and holes 32 provided in aflange portion 34 of the bearing assembly or main bracket 18. The rivets28 may also be utilized to structurally associate one end portion of theband 12 with the bearing assembly or main bracket 18 as by extending therivets 28 to pass through holes 36 provided adjacent one end portion ofthe band 12.

The worm gear assembly 20 may comprise a worm gear shaft 38 secured withthe main bearing assembly or bracket 18 for rotation relative thereto,as by means of straps 42 and 44. The straps 26 may be secured, as bymeans of rivets 40 extending through apertures 41 and 43 provided in thestraps 26 and worm gear shaft 38, respectively. Accordingly, upon,rotation of the worm gear assembly 20, the end portions of the straps26 will be wound about the worm gear shaft 38, :decreasing the freelength of the straps 26 and, accordingly, decreasing the circumferencecircumscribed thereby and constricting t he band 12 about the piston 14.

The worm gear shaft 38 may be supported for rotation by, for example,outer and inner bearing portions 42 and 44, respectively of the bearingassembly or main bracket 18. For example, the bearing portions 42 and 44may comprise strap portions defined by the outer margins of the bearingassembly or main bracket 18 and a plurality of generally rectangularapertures 46 provided therein, the straps being formed into generallycylindrical configuration, as shown, around the worm gear shaft 38 andsecured in such position by, as means of outer and inner rivets 48 and50, respectively, extending through the overlapping portions of thebearing assembly or main bracket 18, as shown. The inner rivets 50 mayfurther extend through the base 52 of the pivot bracket 22 (see FIG. 2)to secure the pivot bracket 22 relagve tg the bearing assembly or mainbracket 18.

As heretofore pointed out, the straps 26 be secured t end portion hereof.w htt bse asas m fly 25 main bracket 18, as by means of rivets 28 andat the other end portions with the worm gear shaft 38, as by rivets 40.The end portions secured with the worm gear shaft 38 may, for

example, be disposed generally within the rectangular apertures 46, thatis, between the outer and inner bearing portions 42 and 44 of thebearing assembly or main bracket I i The worm gear shaft 38 may beprovided with means, such as, for example, a screw slot 54 and/orhexagonal portion 56 to enable the shaft 38 to be directly rotated, asby means of a screwdriver, wrench, or the like, to wind the straps 26thereon or unwind the straps 26 therefrom.

The worm gear assembly 20 may further comprise a worm gear 58structurally associated with the worm gear shaft 38, for example,generally medially thereof. The worm gear 58 may be secured with theworm gear shaft 38 for rotation theravith in substantially any desiredmanner, for example, by means of set screws, rivets, press fitting,braising, welding, staking, or the like, or may be integrally formedtherewith, as by stamping, forging, machining, or the like. The wormgear 58 may, for example, comprise a plurality of helical teeth 60disposed about the periphery thereof.

The worm gear 58 may be of substantially any desired thickness, forexample, extending generally entirely between the inner bearing portions44 to retain the worm gear assembly 20 against axial movement relativeto the bearing assembly or main bracket 18.

The pivot bracket 22, as heretofore pointed out, may be structurallyassociated with the main bracket or bearing assembly- 18 by means, suchas the rivets 50 extending through the base 52 of the pivot bracket 22and the bearing assembly or main bracket 18. The pivot bracket 22 may beof generally U-shaped configuration comprising, for example, in additionto the base portion 52 a pair of generally rectangular arms 62 extendingsubstantially perpendicularly outwardly of the base portion 52.Accordingly, the arms 62 will be generally parallel to each other and tothe sides of the worm gear 58.

Ba Qifhi smell 9! "i t 9 bracket 22 219; 2E vided with an aperture 64extending therethrough. The apertures 64 may be generally axialalignment with each other and, there may be disposed therein a pivot pin66 which,

accordingly, will extend bet ween the arms 62 of the pivot bracket 22and upon which the worm screw bracket 24 may be pivotally supported, aswill be described in more detail hereafter.

The worm screw bracket may, for example, be formed of sheet metal so asto comprise a back wall 68, a pair of side walls 7 0 an end wall 72 anda central wall 74. The back wall 68 may, for example, be provided with agenerally rectangular aperture 76 formed by folding a portion thereofalong a fold line 78 to a substantially right angle bend to define thecentral wall 74. Similarly, the end wall 72 may be formed by folding agenerally rectangular tongue along a fold line 80 to a generally rightangle position and the side walls 70 may be similarly formed.

The central wall 74 may be provided with a generally circular aperture82 and the end wall 74 may be provided with a slot 84 in generalalignment therewith. A worm generally designated by the referencecharacter 86 and comprising, for example, spiral threads 88, a generallycylindrical nose 90 at one end portion thereof, a generally cylindricalshoulder 92 at the other end portion thereof, and a head portion 94extending generally outwardly of the shoulder 92. The head portion 94may be provided with means, such as a screw slot 96 and hexagonal flats98 to enable engagement thereof by a torque producing tool, such as awrench or screwdriver. The worm screw 86 may be rotationally carried bythe worm screw bracket 24 as by having the nose 90 thereof engagedwithin the aperture 82 andthe shoulder 92 thereof engaged within theslot 84.

The worm screw bracket 24 and the worm screw 86 may, as heretoforepointed out, be pivotally associated with the mam bracket 18, as by thepivot bracket 22 and pivot pin 66.

The worm screw 86 may, therefore, be moved between a position whereatthe threads 88 thereof engage the teeth 60 of the worm gear 58, as shownin solid lines in FIG. 2 and a position whereat the worm thread 88 isdisengaged from the teeth 60 of the worm gear 58, as shown in phantom inFIG. 2. The worm screw bracket 24 may be biased toward the threadengaging position of the worm screw 86, as by means of a pair of hairpinsprings 100 disposed about the pivot pin 66 and engaging the baseportion 52 of the pivot bracket 22 and the back wall 68 of the wormscrew bracket 24. The back wall 68 and the side walls 70 opposite theworm screw 86 may, as illustrated, comprise a handle portion which, upondepression thereof, will release the worm threads 88 from the gear teeth60, against the biasing of the hairpin springs 100.

The worm screw 86 may, when constructed and arranged as described above,serve at least two functions. Firstly, the worm threads 88 may functionas a pawl with the teeth 60 of the worm gear 58 functioning as a ratchetto enable direct, anti-reverse windup of the straps 26 on the worm gearshaft 38 by being cammed outwardly by the gear teeth 60 so as to rotatethe bracket 24 to the position shown in phantom in FIG, 2 and enable thegear teeth 60 to move transversely the worm tooth 88 when the piniongear 58 is rotated in a strap winding direction and, secondly, byrotation of the head portion 94 of the worm screw 86 as a torqueincreasing, slow speed worm and pinion drive for slow speed windup andrelease of the straps 26. Regardless of whether the worm gear shaft 38is rotated directly, as by the screw slot 54 for high speed windup ofthe straps 26 or indirectly, through rotation, for example, of the screwslot 96, the worm thread 88 functions for anti-reversal of the gearshaft 38 until the handle portion of the worm screw bracket 24 isdepressed to the position shown in phantom in FIG. 2 to enable rapidrelease or unwinding of the straps 26.

Accordingly, by direct rotation of the gear shaft 38, a fast and rapidwindup or takeup of the straps 26 may be effectuated to rapidly closethe clamp 10. Finer adjustment may then be readily and easilyaccomplished by rotation of the worm screw 86, which fine adjustmentwould be continuous in range. Hence, no re-setting of the worm screw 86is required between uses of the clamp 10, since the worm screw 86 may betightened at any time without requiring any release between tightenings,such as would be required if ordinary screw thread fasteners wereutilized for fine adjustment of the straps 26.

It may be readily seen that the worm bracket 24, therefore,

may be defined as comprising a generally box-like portion 102 having endwalls defined by the end wall 72 and the central wall 74 and a generallyopen and unobstructed side designated by the reference character 104 anda handle or manual operating means 106 disposed in general alignmenttherewith and extending generally perpendicularly outwardly of one ofthe end walls, namely the central wall 74 with the pivot pin 66 beingdisposed generally adjacent the intersection therebetween. It may befurther seen that the hairpin springs 100 may be defined as comprising aloop portion 108 disposed about the pivot pin 66 and leg portions 110and 112 engaging the worm bracket 24 and pivot bracket 22, respectively.The band means 12 may be further provided with generally outwardlyextending means, folds or projections 114 adapted to abut the uppersurface of a cylinder, or t hel ike, to position the piston ringcompressor 10 properly relative thereto during movement of the piston 14into the bore thereof.

While the invention has been described, disclosed, illustrated and shownin terms of an embodiment or modification which it has assumed inpractice, the scope of the invention should not be deemed to be limitedby the precise embodiment or modification herein described, disclosed,illustrated or shown, such other embodiments or modifications as may besuggested to those having the benefit of the teachings herein beingintended to be reserved especially as they fall within the scope andbreadth of the claims here appended.

What is claimed is: for use as a piston ring compressor furthercomprising an 1. Band-type clamp comprising, in combination, anelongated band of substantial width disposed generally elongated strap,rotatable means for engaging said strap to interiorly of said strap andadapted to engage piston rings proyfi tension thereto when rotated,means fgt rotating to t r a n smit the constriction of said strapgenerally uniformly said engaging means to provide a rapid slack takeupand 5 t eretofsaid elongated band being provided with gene rallyrelease, gear means for rotating said engaging means at a outwardlyextending means adapted to engage a cylinder reduced rate to provide aslower speed and higher force block during piston insertion to providepositioning relative takeup and release and means for automaticdisengagement thereto. of said gear means during direct rotation of saidrotating 11. A band-type clamp comprising, in combination, an means in atension increasing direction wherein said diselongated strap, a shaft,bearing means for supporting said engagement means further comprisesmeans for maintaining shaft for rotation in generally tangentialrelationship with engagement between said rotating means and said gearmeans said strap for winding of said strap thereabout to provide whensaid rotating means is not rotating inatension increastension thereto,means for rotating said shaft at a first ing direction and wherein saidgear means comprises a selfratio for enabling rapid slack takeup andrelease, driven locking gear train to enable functioning thereofasaratchetgear means operatively associated with said shaft for typeanti-reverse structure. rotation therewith, driving gear means adaptedfor driving 2. Band-type clamp comprising, in combination, anelonengagement with said driven gear means, means for enabling gatedstrap, rotatable means for engaging said strap to prorotation of saiddriving gear to provide a second ratio drive vide tension thereto whenrotated, means for rotating said of said shaft for a slower speed andhigher force takeup and engaging means to provide a rapid slack takeupand release release and means for movably mounting said driving gear andgear means for rotating said engaging means at a reduced means relativesaid beating means to enable movement for rate to provide a slower speedand higher force takeup and selective engagement and disengagementbetween said release, wherein said rotatable means comprises a shaft anddriving and driven gear means.

bearing means for supporting said shaft for rotation in gener- 2 12.Band-type clamp defined in claim 11 further comprising ally tangentialrelationship with said strap, wherein said a i g bracket, Said bearingmeans being mounted with gear means comprises driven gear meansoperatively assaid bearing bracket and wherein said mounting meanssociaggd with said shaft for rotation therewith, driving gear comprisesa worm bracket mounted with said bearing bracket means adapted fordriving engagement with said driven gear for pivotal movement relativethereto about an axis generally means at a torque increasing ratio andmeans for enabling lparallel and spgtgd apartf n said shaft and ofbiasing said rotation of said driving gear means and wherein saidrotating W m b a IOWardS gear engagement t0 enable rotation meanscomprises means mounted with said shaft for enabling of said driven gearmeans in one direction to pivot said worm direct rotation and means forenabling said driven gear bracket toward gear disengagement to provideratchet-like means to overrun and rotate independently of said drivinganti-reverse action.

gear nsiq n eas t d rit am- .35. BancHxpe aiefias in al i lhg lsai 3.Band-type clamp defined in claim 2 wherein an end driving and drivengear means comprise, respectively, mating portion of said strap isstructurally associated with said worm and pinion gears.

shaft enabling rotation of said shaft to wind said strap end 14.Band-type clamp defined in claim 13 further comprising portionthereabout. manual operating means for pivoting said worm bracket 4.Band-type clamp defined in claim 3 wherein the other towards geardisengagement for enabling rapid release of end portion of said strap ispositioned relative to said bearing said clamp.

means to define aconstricting type encircling band clamp. 15. Band-typeclamp defined in claim 14 wherein an end 5. Band-type clamp defined inclaim2 wherein said driving portion of said strap is structurallyassociated with said and driven gear means comprise, respectively,mating shaft to enable rotation of said shaft to wind said strap endworm and pinion gears. I thereabout.

6. Band-type clamp defined in claim 5 further comprising 16. Piston ringcompressor comprising, in combination, a bearing bracket for fixedlypositioning said bearing means an elongated band of substantial widthadapted to be disposed and a worm bracket structurally associated withsaid bearing with the ends overlapping in encircling relationship to abracket for pivotal movement about an axis generally parallel piston, abearing bracket structurally associated therewith the axis of saidshaft, wherein said pinion gear is mounted adjacent the outer endportion thereof, a shaft rotationally generally concentrically with saidshaft and wherein said supported by said bearing bracket in generallyspaced apart worm shaft is mounted with said worm bracket for rotationparallel relationship to said band, a pair of spaced apart about an axisgenerally perpendicular the pivot axis and generally parallel strapsdisposed generally externally generally in the plane of said pinion gearto enable pivotal medially of said band and secured relative theretogenerally movement of said worm bracket to provide engagement andadjacent said bearing bracket with free end portions thereof xdisengagement of said worm and said pinion gear. being secured generallytangentially with said shaft to enable 7. Band-type clamp defined inclaim 6 further comprising .rotation of said shaft to wind s aid strapthereabout to conmeans for biasing said worm bracket towards gearengagestrict said band, gear means for rotating said shaft, means forment to enable said worm to provide ratchet-type antienabling selectivedrive of said shaft directly for course reverse holding of said piniongear. 0 adjustment, means for disengaging said gear means during 8.Band-type clamp defined in claim 7 wherein said shaft such courseadjustment, and means for driving id gait is constructed and arranged toenable direct, low mechanical 'at increasedwq ue through said gear meansfor fine advantage and rapid takeup rotation thereof, said wormadjustment. being constructed and arranged to enable direct rotation 17.Piston ring compressor comprising, in combination,

thereof for high mechanical advantage slow speed takeup an elongatedband of substantial width adapted to be disand release rotation of saidshaft and said worm bracket is posed with the ends overlapping inencircling relationship constructed and arranged to enable manualmovement to a piston, a bearing bracket structurally associatedtherethereof to provide gear disengagement for rapid release withadjacent the outer end portion thereof, a shaft rotationrotation of saidshaft. .ally supported by said bearing bracket in generally spaced 9.Band-type clamp defined in claim 2 wherein said apart parallelrelationship to said band, a pair of spaced pinion gear is disposedgenerally longitudinally medially of apart generally parallel strapsdisposed generally externally said shaft and wherein there is provided apair of elongated medially of said band and secured relative theretogenerally straps structurally associated with said shaft on oppositeadjacent said bearing bracket with free end portions thereof sides ofsaid pinion gear. 7 being secured generally tangentially with said shaftto enable l0. Band-type clamp defined in claim9 particularly adaptedrotation of said shaft to wind said strap thereabout to constrict saidband and gear means for rotating said shaft comprising, in turn, adriven pinion gear mounted for rotation with said shaft generallybetween said free end portions and a worm positioned for engagement withsaid pinion gear for driving and locking said shaft. 7 V 7 7 l8.Pistonring compressor defined in claim 17 further comprising a wormbracket for selectively movably positioning said worm in engagement withsaid pinion gear and disengaged therefrom to enable direct rotation ofsaid shaft.

19. Piston ring compressor defined in claim 18 further comprising meansfor biasing said worm bracket towards gear engagement enabling said wormto provide ratcheting of said pinion gear.

said worm bracket comprises a generally box-like portion having spacedapart end walls and at least one generally open and unobstructed side,said worm being rotatably carried by said end walls and accessiblethrough said generally open and unobstructed side, and wherein there isfurther provided a pivot bracket positioned relative to said bearingbracket and comprising a pair of generally parallel spaced apart armsand a pivot pin extending through said arms and said worm bracket ingenerally parallel spaced apart relationship to said shaft, enablingsaid worm bracket to be pivoted about said pivot pin to enable saidpinion gear to extend through said generally open and unobstructed sideand into engagement with said worm.

21. Piston ring compressor defined in claim 20 wherein said worm bracketfurther comprises a handle portion extending generally perpendiculary ofone of said end walls andin general alignment with said box-likeportion, wherein said pivot pin passes through said worm bracketgenerally at the intersection of said box-like portion and said handleportion, wherein said biasing means comprises at least one hairpin typewire spring having a loop disposed on said pivot pin and a pair of legsextending therefrom and engaging said pivot and worm brackets,respectively, and wherein said pivot bracket arms extend generallyoutwardly of said bearing bracket, straps and band, enabling inwardrocking movement of said handle portion to provide outward rockingmovement of said box-like portion.

22. Piston ring compressor defined in claim 21 wherein said bearingbracket comprises a pair of inner generally ring-like bearing portionsdisposed on opposite sides of said pinion gear and extending generallybetween said pinion gear and said straps and a pair of outer generallyring-like bearing portions disposed adjacent the outside edges of saidstraps to thereby securely position said shaft and straps relative tosaid bearing bracket.

23. Piston ring compressor defined in claim 17 wherein at least one endportion of at least one of said shafts and said worm is constructed andarranged to enable torque transmitting engagement thereof with at leastone of a screwdriver and a wrench.

24. Machine for enabling the application of constricting, constraining,restraining, tensioning, moving or like forces to an object, apparatus,structure, assembly or the like comprising, in combination, a bracket;elongated means having at least a portion thereof adapted to be disposedrelative to such object, apparatus, structure, assembly, or the like,for the transmission of force thereto and at least another portionthereof adapted for movement relative to said bracket; and multipleratio means structurally and operatively associated with said bracketand said elongated means for enabling the selective exertion of forcesto said elongated means tending to induce movement thereof relative tosaid bracket, said multiple ratio means comprising, in turn, shaft meansrotatably mounted with said bracket for pulling said elongated meansduring rotation thereof, means for enabling direct rotation of saidshaft means, a pinion gear mounted for rotation with said shaft, adriving gear mounted for selective engagement and disengagement withsaid pinion gear and means for driving said driven gear for reduced rateand increased torque rotation of said shaft means, enabling said machineto selectively transmit, maintain and release such constricting,constraining, restraining, tensioning, moving or like forces to suchobject, apparatus, structure, assembly, Q ike

1. An apparatus for shop assembly of superheater or reheater modulescomprising: a fixed reference base, a first support means mounted onsaid base, an upstanding structural frame tower mounted on said base,accurately machined surfaces particularly positioned on said structuralframe tower, a second support means for supporting in a verticalorientation a segment of a header to which tubes supported by said firstsupport means are to be joined to form said super-heater or reheatermodule, and means for accurately positioning said second supportingmeans on said machined surface of said structural frame tower so as tomaintain a particular relationship to said firs support means.
 2. Theapparatus of claim 1 wherein said accurately machined surfaces includeplural transverse elements fixed to said structural frame tower atspaced vertical intervals.
 3. The apparatus of claim 2 wherein the meansfor positioning said second support means includes at least one mountingplate, said at least one mounting plate supported by and transverselymovable with respect to said machined surfaces of said structural frametower, said mounting plate further having complementary accuratelymachined surfaces mating with said machined surfaces of said structuralframe tower.
 4. The apparatus of claim 3 wherein the means forpositioning said support means includes plural mounting plates,relatively movable with respect to each other for accurate relativepositioning thereof.
 5. The apparatus of claim 3 wherein said secondsupport means further includes a header support base mounted on said atleast one mounting plate.
 6. The apparatus of claim 5 wherein saidheader support base includes a longitudinal trackway and a plurality ofV-slide assemblies mounted on said trackway for selective relativemovement with respect thereto.
 7. The apparatus of claim 6 wherein saidV-slide assemblies include a base plate slidable along said longitudinaltrackway, a standard extending outwardly from said base plate, saidstandard having guide bearings thereon, a plate slidably mounted in saidguide bearings having a V-shaped notch in one end opposite said bottomplate for adjustable support engagement with said header, and aretention means for retaining said header against said V-shaped notch.8. The apparatus of claim 7 wherein said retention means is anadjustable cable means entrained about saId header and fixed at its endsto said base plate.
 9. The apparatus of claim 7 wherein said headersupport base further includes a first jack means for moving said plateof said V-slide assemblies in said guide bearings, and a second jackmeans for positioning said header longitudinally with respect to saidheader support base.